Stephania japonica var. discolor (Blume) Forman
Forman, L.L. (1956) Kew Bulletin 11: 56.
Vine, Tape; Stephania; Snake Vine; Vine, Snake; Tape Vine
A slender vine not exceeding a stem diameter of 2 cm.
Leaf blades peltate, about 7-18 x 7-15 cm, petioles about 5-10 cm long.
Male flowers: Inflorescence consists of a number of umbels, each containing seven or eight heads. Each head contains about 15-17 flowers. Sepals eight, each sepal spathulate, about 1 mm long. Petals four, each petal obtriangular, about 0.6-0.7 mm long. Anthers fused together to form a stalked disk-like structure in the centre of the flower. Anther disk about 2.5 mm diam., and about 1-1.2 mm high, stalk about 1.5-2 mm long. Anthers opening by means of a single slit around the margin of the disk. Female flowers: Inflorescence consists of a number of umbels each containing about five heads. Each head containing 6-10 flowers. Sepals about 1 x 0.5 mm. Petals about 0.8 x 0.7 mm. Stigmas usually three-lobed.
Fruiting carpels usually in groups of 2 to 8 but sometimes solitary. Each carpel about 5-7 x 5-7 mm, laterally compressed, style remnant lateral, close to the base of the fruiting carpel. Endocarps, curled up like a prawn, +/- orbicular, about 4-5.5 mm diam. Surface sculptured. Embryo U-shaped, about 15 mm long, Radicle curved, about 10-11 mm long, longer than the curved cotyledons (4 mm long.)
Cotyledons linear, about 13-17 x 1-3 mm, venation obscure, longitudinal and parallel. First pair of leaves cordate to triangular or almost orbicular, about 15 mm diam., peltate, petiole about 11 mm long. At the tenth leaf stage: leaf blade cordate to almost orbicular, about 4.5 cm diam., apex obtuse to acuminate, base cordate to truncate, peltate, margin entire to coarsely and sparsely toothed, petiole about 5-8 cm long. Usually five to seven veins, including the midrib, radiating from the point of attachment of the petiole to the leaf blade. Seed germination time 49 to 51 days.
Roots and tubes of this species are bitter and chemical investigations have shown the presence of a considerable concentration of a large number of alkaloids; more than 20 different alkaloids have been isolated from the plant and identified. Cribb (1981).